Project Summary/Abstract Confusion, being lost, and losing track of one's orientation within large or unfamiliar indoor spaces - these are some of the biggest challenges facing people with visual disabilities. Since GPS typically doesn't work indoors, and isn't fine-grained enough anyway, individuals who cannot readily access visual information are at a significant disadvantage, and many blind individuals choose to avoid venturing into unfamiliar territory unless absolutely necessary, thus are often deprived of many of the social and economic opportunities available to others. This SBIR Phase II application proposes a technology solution to address the indoor navigation needs experienced by people with disabilities. It has several advantages over other wayfinding approaches, in that it requires no infrastructure in indoor spaces nor does it require maps to be created prior to navigation. Thus it is applicable to any unfamiliar indoor or outdoor space. We present a Research Plan that builds on a successful Phase I, in which participants experienced substantial improvements in navigation ability when using a proof-of-concept device. The Phase II project includes building an improved, miniaturized hardware device, performing a human-subjects study to measure the positional accuracy of the sensor technology, implementing a fully-functional smartphone app, iteratively conducting periodic pilot studies as the technology progresses, and finally conducting in-clinic and take-home studies in which potential end users use the device in their everyday lives. In addition, the project includes the creation of a crowd-sourced database by which users of the product will be able to share or augment navigation data from new venues. The project will thus prove the functionality and user-acceptance of a product for improved indoor navigation, giving insights into the degree to which it enhances users? quality of life.